Raising hopes for an effective intervention in diagnosing the risk of early onset of disease, German scientists have developed a new blood test that can detect Alzheimer’s long before the first symptoms appear in patients.

Alzheimer’s disease is thought to begin long before patients show typical symptoms like memory loss.The team, led by Klaus Gerwert, professor at Ruhr University Bochum in Germany, noted that one of the hallmarks of Alzheimer’s disease is the accumulation of amyloid-beta plaques in the patient’s brain.

Alzheimer’s can now be detected using a blood test.Pixabay

The findings, published in the journal EMBO Molecular Medicine, showed that the blood test uses a technology called immuno-infrared sensor to measure distribution of pathological and healthy structures of amyloid-beta in the blood.

The pathological amyloid-beta structure is rich in a sticky, sheet-like folding pattern that makes it prone to aggregation, while the healthy structure is not.

The two structures absorb infrared light at a different frequency, allowing the blood test to determine the ratio of healthy to pathological amyloid-beta in the sample.

The pathological form is a misfolded version of this molecule and known to initiate the formation of toxic amyloid-beta molecules that starts accumulating in the brain 15 to 20 years before disease onset.

They found that the test reliably detected amyloid-beta alterations in the blood of participants with mild cognitive impairment that also showed abnormal amyloid deposits in brain scans. In order to detect blood changes well ahead of disease onset, the researchers compared blood samples of 65 participants that were later in the follow-up studies diagnosed with Alzheimer’s disease with 809 controls.

This can be very beneficial for potential Alzheimer’s patients. Flickr

The assay was able to detect signs of the disease on average eight years before diagnosis in individuals without clinical symptoms with an overall diagnostic accuracy of 86 per cent. The blood test would thus offer an opportunity to identify those at risk and may thereby open the door to new avenues in drug discovery, the researchers said. IANS

A future non-invasive eye test may allow early detection of Alzheimer’s disease before memory loss kicks in, say a team led by an Indian-origin researcher.

Retina being an extension of the brain, the optical coherence tomography angiography (OCTA) will check patients’ vision as well as brain health, said the study published in the journal Ophthalmology Retina.

The researchers said that loss of blood vessels in retina would reflect changes in the brain, be it for both healthy people or Alzheimer’s patients.

“We know that there are changes that occur in the brain in the small blood vessels in people with Alzheimer’s disease, and because the retina is an extension of the brain, we wanted to investigate whether these changes could be detected,” said lead author Dilraj S. Grewal, ophthalmologist at Duke University.

Using the OCTA that uses light waves that reveal blood flow in every layer of the retina, the researches checked more than 200 people.

A lady suffering from Alzheimer’s. Flickr

They found that in people with healthy brains, microscopic blood vessels form a dense web at the back of the eye inside the retina — as was seen in 133 participants in a control group.

Conversely, in the eyes of 39 people with Alzheimer’s disease, that web was less dense and even sparse in places.

The OCTA machines, relatively a new noninvasive technology, measures blood vessels that cannot be seen during a regular eye examination.

“It’s possible that these changes in blood vessel density in the retina could mirror what’s going on in the tiny blood vessels in the brain, perhaps before we are able to detect any changes in cognition,” added Sharon Fekrat, ophthalmologist at the Duke University in the US. (IANS)